Remote control system



REMOTE CONTROL SYSTEM Filed Sept. 24, 1930 D.C. or

m R 1 F I g E I I'L lNl/ENTOR 51F. WATSON By ATTORNEY Patented Feb. 21,1933 UNITED STATES PATENT OFFICE i EDWARD F. WATSON, OF LARCHMONT, NEWYORK, ASSIGNOR T AMERICAN TELE- PHONE AND TELEGRAPH COMPANY, ACORPORATION OF NEW YORK REMOTE CONTROL SYSTEM Application filedSeptember 24, 1930. Serial No. 484,130.

' This invention relates to a remote control system and moreparticularly to a method of and system for controlling the motors of aprinting telegraph set from a distant transmitting station.

An object of this invention is to conveniently and eflectively start andstop the apparatus at the printing telegraph station from the remotecontrol station.

It is well known in the art that printing telegraph apparatus at adistant station may be conditioned for receiving or transmitting signalsby the operation of a power switch at that station which will, in turn,apply power to start the motor mechanism for the printer set. The motorswill then revolve until stopped by opening the switch. This methodinvolves continual use of the driving means during the interval signalsare not being transmitted over the system and has proven to beuneconomical. The unnecessary use of power, the continual wear and tearon revolving parts and the required presence of an attendant to manuallyoperate the power switch add greatly to the maintenance cost of aprinting telegraph system. These clifficulties are obviated in systemsin accordance with the present invention.

An advantage of this invention is that the circuit may be designed tofunction with open and closed signals as well as with positive andnegative signals.

Broadly, this invention comprises a circuit for controlling the motormechanism at a remote printing telegraph station from a distanttransmitting station.

In accordance with the principles underlying this invention, the motorsof any num- .ber of remote stations may be controlled simultaneouslyfrom a control station by arranging the line and printer relays of eachremote station in series with the transmission line.

Referring to the drawing, A represents a transmitting station and B adistant printer station. Control station A is of a type well known inthe art and comprises a sending relay TR and a motor control key K forconditioning the equipment at A for transmitting signals, A telegraphline TL extends between stations A and B. Polar relay LR and polarizedprinter magnet or relay PM are serially connected in the telegraph linecircuit at B. If it is desirable to transmit open and closed signalsover the system, LR and PM may be provided as neutral relays instead ofpolar relays. Belay SR is a slow release relay and is arranged in alocal circuit to respond to the operation of polar relay LR for startingand stopping the printer motor or motors M. This will be describedsubsequently. Although only one station B is shown in connection withthe drawing it will be understood that any number of stations may beserially connected in the circuit by arranging the polar relay andprinter relay of each station in series with the transmission line.

The manner of operation of the motor control arrangement will now bedescribed in detail. The actuation of key K to the right will conditionthe equipment at A for transmitting signals. The operation of sendingrelay TR to its marking contact will cause the transmission of a markingimpulse over telegraph line TL which will operate polar relay LR andprinter magnet PM connected in series with the line. The operation ofrelay LR to its marking contact in response to the marking signal willoperate slow release relay SR over a circuit traced from battery throughresistance R and the winding of relay SE to ground on the markingcontact and armature of polar relay LR. Control relay GB is normallyheld operated on a circuit traced from battery through resistance Rbreak contact of relay SE to ground through the winding of relay CR.

The operation of relay SR, as hereinbefore over telegraph line TL willcause polar relay LR to move to its spacing contact, in turn releasingrelay SR after a short interval of time. The release of relay SE tonormal will cause the operation of relay CR and the consequent stoppingof the motor driving means M. In this manner, the motor mechanism ofprinter set B will be under the control of the transmitting station andwill start in response to a marking signal and will continue to runwhile message signals are being transmitted, automatically disconnectingitself when a spacing impulse is impressed on the line for a givenminimum interval greater than the interval of any spacing impulse in theregular transmission of message signals.

The circuit comprising the resistance R in series with condenser C,connected be- 89 tween the marking contact and armature of polar relayLR, is a spark killer for minimizing the arcing at the contacts of relayLB during operation. Resistances R and R; are provided in cases where itis necessary to limit the current flow through the windings of relays SRand GR.

It is to be understood that this invention is not limited to controllingthe motor of a telegraph station by the precise arrangement of partsdisclosed but may be embodied in other arrangements of relays orequivalent devices to accomplish the desired purpose. For example, A maybe a telegraph station transmitting open and closed signals by means ofa telegraph key.

that is claimed is:

1. Means for controlling the motor mechanism of a printing telegraph setfrom a remote transmitting station comprising a printer set, acontrolcircuit extending from sense for starting the motor driving meansof said printer station, said slow-releasin means responding differentlyto a sustaine energization of said relay in another sense for stoppingthe motor driving means of said printer station.

3. In a telegraph system, a transmitting station, a recording station, aline connecting both of said stations, power mechanism at said recordingstation for conditioning Said station for receiving, means at thetransmitting station for impressing marking and spacing current impulsesof different polarity upon said line, circuit controlling devices atsaid recording station including a slow release relay responsive to amarking current impulse (of one polarity) for thereafter applying powerto said power mechanism to cause it to condition said recording stationfor receiving during the transmission 0 message signals, said circuitcontrolling devices being responsive to the transmission of a spacingcurrent impulse of another polarity of a duration longer than anyspacing impulse included in the regular message signals for removing theapplied power from said power mechanism.

In testimony whereof, I have si ed my day of name to thisspecificationthis 23r September, 1930.

EDWARD F. WATSON.

said set to the transmitting station, a polar line relay in said controlcircuit responsive to impulses of current over said circuit, aslow-releasing relay under control of said polar line relay, anadditional relay for applying power to the motor mechanism of saidprinter set, said additional relay being normally energized from acontact on said slow-releasing relay and adapted to supply power to saidmotor mechanism subsequent to the operation of said slow release relayand consequent to the release of said additional relay.

2. In combination, in a printing telegraph system, a transmittingprinting telegraph set, a remote printer station, motor driving means atsaid station, a telegraph line extendingfibetween said set and saidstation, and adapted to be energized by telegraph line current from saidtransmitting set, a polar relay at said remote station seriallyconnected in said line and responsive to said line current, aslow-releasing relay respondmg to the continuous energizatlon orintermittent energization of said relay in one gas

